I have asp:TextBox to keep a value of money, i.e. \'1000\', \'1000,0\' and \'1000,00\' (comma is the delimiter because of Russian standard).
What
We use this very liberal regular expression for money validation:
new Regex(@"^\-?\(?\$?\s*\-?\s*\(?(((\d{1,3}((\,\d{3})*|\d*))?(\.\d{1,4})?)|((\d{1,3}((\,\d{3})*|\d*))(\.\d{0,4})?))\)?$");
It allows all these: $0, 0, (0.0000), .1, .01, .0001, $.1, $.01, $.0001, ($.1), ($.01), $(.0001), 0.1, 0.01, 0.0001, 1., 1111., 1,111., 1, 1.00, 1,000.00, $1, $1.00, $1,000.00, $ 1.0000, $ 1.0000, $ 1,000.0000, -1, -1.00, -1,000.00, -$1, -$1.00, -$1,000.00, -$ 1, -$ 1.00, -$ 1,000.00, $-1, $-1.00, $-1,000.00, $(1), $(1.00), $(1,000.00), $ (1), $ (1.00), $ (1,000.00), ($1), ($1.00), ($1,000.00)